Rowing Machine Exercise-Assisting Device

ABSTRACT

The present invention relates to an exercise-assisting device, and more specifically to a seat able to move reciprocally automatically in the front-to-back direction, which is one of the constituent elements of a rowing machine constituting a remedial exercise device for physically disabled individuals, and particularly paraplegics, while also constituting a whole-body exercise device able to prevent heterotopic ossification.

TECHNICAL FIELD

The present invention relates to an exercise-assisting device, and moreparticularly, to a rowing machine exercise-assisting device that isprovided with a seat capable of automatically moving reciprocally inforward and backward directions, which is one of the components of arowing machine.

BACKGROUND ART

A rowing machine is a whole body exercise device configured to consume asubstantial large amount of energy within a short period of time, whichis manufactured by obtaining an idea from rowing operations carried outin rowing races on the water, so as to lively provide rowing rhythms andfeelings to a user using the rowing machine indoors. The rowing machinehas similar exercise strength to that of a stepper or a running machinefocused to lower body exercises, but it is very effective in performingthe whole body exercise. Further, since the user exercises while sittingin a seat mounted on the rowing machine, no harm is applied to his kneeareas. In case where the rowing machine is provided with a monitor, theexercise results can be recorded and stored through the monitor and astoring device, while the exercise state is being monitored in realtime. The rowing machine is well known in Europe, Australia, Japan andso on, and some rowing machine products are capable of performingon-line racing through the connection of Internet with other countries,thereby avoiding boring during the exercise. Also, since the rowingmachine does not have any noise generated therefrom and is light inweight, it can be used indoors, without any trouble in installationareas.

The rowing machine is usually used for training athletes in manycountries, and as mentioned above, since the exercise is performed whilethe user is sitting in the seat, no harm is applied to the user's bodyareas, so that the rowing machine is also used as a remedial exercisemachine for a medical purpose.

Referring to FIGS. 1A and 1B, now, an operating method of the rowingmachine is described. A user sits in a seat capable of reciprocallymoving in forward and backward directions on a rail connected to a bodyof the rowing machine and then places his soles of feet on footboards.Next, he takes a handle of the rowing machine. The user applies a givenforce to his feet on the footboards, and at the same time, he bends hisback and waist backwardly, so as to pull the handle toward his chest byusing the force generated from his back and waist. At this time, hisknees and legs are fully stretched out, and the reciprocally moving seatis moved to the rear side of the rail. This state is maintained forseveral seconds after the pulling operation so as to allow his musclesto be sufficiently contracted. After that, if the force applied from hisback and waist is removed, the handle is moved to its original positionby means of the restoring force thereof. At this time, his back andwaist are bent in a forward direction in which the body of the rowingmachine is placed. Also, the seat is moved forwardly, so that his kneesare automatically bent to return to the initial state of the rowingoperations. The rowing operations are repeatedly carried out to obtainwhole body exercise effects.

Through the repetition of the above-mentioned rowing operations, themuscles on the user's back, shoulder and low body are strengthened, andaerobic exercise for the user's whole body is performed, so that therowing machine is used for the remedial purposes for disabled personscaused by unexpected accidents as well as for training purposes forprofessional athletes.

In addition to the above-mentioned purposes, especially, the rowingmachine can be used for disabled persons who do not move their legs atall by the paralysis of the lower body. The paraplegic disabled personcannot bend his knees willingly, and thus, he lives in a state where hisknees are stretched out. In this case, calcium accumulates on givenjoints like knees, and if a long period of time has passed in thisstate, the calcium is just hardened to cause the joints to be interferedin the movements. In severe cases, new bone pieces form at abnormalpositions. This is called heterotopic ossification. The heterotopicossification is the process by which bone tissue forms in connectivetissues or soft tissues since oxygen supply to the tissues isinsufficiently performed and minute injuries are caused on the tissues,and as mentioned above, the heterotopic ossification often occurs in theparaplegic disabled persons caused by the spine injury. Specifically,the heterotopic ossification most commonly occurs in hip joints, and itis generally found in knee joints. Therefore, the knees of theparaplegic disabled persons are forcedly bent and stretched out inhospitals and the like.

According to the seat attached on the conventional rowing machine, auser bends his knees and applies a given force to the footboards. Next,he stretches his knees and pulls the handle, thereby performing therowing operations. Therefore, if the user uses the conventional rowingmachine for remedial and medical purposes, he should apply a given forceto the footboards by using his lower body so as to obtain good exerciseeffects therefrom.

The patient having the spine injury, especially, the paraplegic patient,makes use of the rowing machine in hospitals or houses for the remedialpurposes, but since he cannot use his lower body, the handle of therowing machine is repeatedly pulled and released by using only his upperbody, especially his arms. In this case, therefore, the rowingoperations are achieved by the upper body exercise, especially by thearm exercise, not by the whole body exercise, which does not have anydifference in other arm exercise machines.

In this case, also, since the user repeats the simple arm exercises, heeasily feels bored and does not have any fun, thereby making itdifficult to keep exercising. More particularly, the user cannot takethe active rowing motions of the rowing machine. Therefore, theparaplegic patient does not have excellent whole body exercise effectsand the specific activities of the rowing machine.

Further, since the user performs the upper body exercise in the statewhere his lower body is fixed to the rowing machine, he does not haveany advantage in the prevention of the heterotopic ossification commonlyoccurring to the paraplegic patients, and therefore, the user's kneesshould be forcedly bent or stretched by nurses or caregivers.

DISCLOSURE Technical Problem

Accordingly, the present invention has been made in view of theabove-mentioned problems occurring in the prior art, and it is an objectof the present invention to provide a rowing machine exercise-assistingdevice that is configured to have a seat of a rowing machine adapted tobe automatically moved reciprocally so as to provide whole body exerciseeffects and rowing activities even to patients having spine injury,especially paraplegic patients.

Technical Solution

To accomplish the above object, according to the present invention,there is provided a rowing machine exercise-assisting device including:a guide rail; a support part adapted to support the guide rail; a seatmounted on the guide rail in such a manner as to move reciprocally inforward and backward directions along the length direction of the guiderail, in which a user sits; a safety belt provided on the seat toprevent the user from being escaped from the seat; footboards disposedon left and right sides of the support part to place the user's feetthereon at the time when the user sits in the seat; a fixing beltprovided on each of the footboards to prevent the user's foot from beingescaped from the footboard; a bar-shaped handle taken by the both handsof the user; reciprocating exercise means having a servo motor and acontroller controlling the rotation of the servo motor; and a controlpanel provided on the handle and connected to the controller to transmitcommands to the controller such that the controller controls therotating direction, the rotating speed and the number of rotation of theservo motor, the control panel having a switch adapted to control thestart and stop of the reciprocating exercise of the seat, a switchadapted to adjust the speed of the reciprocating exercise of the seatand a switch adapted to adjust the reciprocating distance of thereciprocating exercise of the seat, whereby as the servo motor rotatesforwardly and backwardly, the seat is automatically moved reciprocallyin the forward and backward directions along the length direction of theguide rail.

According to the present invention, preferably, the reciprocatingexercise means like a timing belt, a chain, or a rack gear and a piniongear is provided in the interior of the support part of the rowingmachine, and through the reciprocating exercise means, the seat movesreciprocally in forward and backward directions along the guide rail ata given speed. If a remedial patient pulls the handle of the rowingmachine in accordance with the rhythms of the reciprocating movements,even the remedial patient, especially the paraplegic patient has therowing feelings like general persons using their lower body.

For example, if the timing belt as the reciprocating exercise means isused, it is rotated in accordance with the rotation of the motor, andthe seat fixed to the timing belt is moved forwardly and backwardly (inthe direction parallel to the surface on which the rowing machine isplaced). The moving direction of the seat is determined in accordancewith the direction of the rotation of the motor. That is, if thedirection of rotation of the motor is changed reversely, the seat ismoved to the opposite direction thereto. Since the motor should repeatthe forward and backward rotation for a relatively short period of time,it is generally used as the servo motor having the controller throughwhich the rotating speed and the rotating direction are accuratelycontrolled, and specifically, a BLDC (brushless direct current) motor ismost desirably used as the motor of the reciprocating exercise means inthe present invention in that the speed and torque can be easilyadjusted just by varying the time (phase difference) of the currentintermittence period of a basic driving circuit, no rectifier and brushgiving bad influences in the life term by means of the abrasion causedby the mechanical friction is used, the life term is semi-permanentlyextended, and noise is generated a little therefrom.

On the other hand, the chain may be used as the reciprocating exercisemeans. If the chain is rotated in accordance with the rotation of themotor, the seat fixed to the chain is moved forwardly and backwardly. Inthe same manner as the above, the moving direction of the seat isdetermined in accordance with the direction of rotation of the motor.

Alternatively, the rack gear and the pinion gear adapted to be engagedcooperatively with each other are used as the reciprocating exercisemeans, thereby moving the seat forwardly and backwardly. That is, as themotor is rotated, the pinion gear connected to the shaft of the motor isrotated, and accordingly, the rack gear engaged with the pinion gearperforms a linear motion. As a result, the seat fixed to the rack gearcarries out the linear motion. In the same manner as the above, themoving direction of the seat is determined in accordance with thedirection of rotation of the motor.

Through the above-mentioned reciprocating exercise means, the remedialpatient can have the rowing activities like general persons, therebyavoiding the simple exercises using only his upper body, especially hisarms.

Further, only if the remedial patient just places his feet on thefootboards, his knees can be bent and stretched by means of the seatreciprocating a given distance in the forward and backward direction.

Advantageous Effect

According to the present invention, as mentioned above, there isprovided the rowing machine exercise-assisting device that is providedwith the seat automatically moves reciprocally in the forward andbackward directions, such that while a patient having spine injury,especially a paraplegic patient performs rowing exercises for remedialand treating purposes, he can enjoy rowing activities, therebyincreasing his interest and fun and allowing him to keep exercising.

In addition to the upper body exercise, especially the arm exerciseperformed in the conventional rowing machine, the present invention canprovide the lower body exercise to the paraplegic patient through theautomatically reciprocating seat, thereby giving the whole body exerciseto him. Further, his knees are automatically bent and stretchedperiodically, thereby preventing the heterotopic ossification by whichthe knee joints are hardened by the accumulation of the calcium on theknees.

DESCRIPTION OF DRAWINGS

FIGS. 1A and 1B are side views showing operating methods of aconventional rowing machine, wherein FIG. 1A shows an initial statebefore a force is applied to the rowing machine and FIG. 1B shows anexercise state.

FIG. 2 is a side view showing a state wherein a handle is pulled towarda user's body by the application of the force to the rowing machine.

FIG. 3 is a partly perspective view showing a support part that is oneof the components of a rowing machine exercise-assisting deviceaccording to a first embodiment of the present invention.

FIG. 4 is a sectional view showing a handle of the rowing machineexercise-assisting device according to the first embodiment of thepresent invention.

FIG. 5 is a side sectional view showing reciprocating exercise meansprovided in the support part of the rowing machine exercise-assistingdevice according to the first embodiment of the present invention.

FIG. 6 is a side sectional view showing reciprocating exercise meansprovided in the support part of a rowing machine exercise-assistingdevice according to a second embodiment of the present invention.

FIG. 7 is a side sectional view showing reciprocating exercise meansprovided in the support part of a rowing machine exercise-assistingdevice according to a third embodiment of the present invention.

BEST MODE FOR INVENTION

Hereinafter, an explanation on a rowing machine exercise-assistingdevice according to preferred embodiments of the present invention willbe in detail given with reference to the attached drawings. The samereference numerals in the drawings denote the same components as eachother.

First, FIGS. 1A and 1B are side views showing operating methods of aconventional rowing machine, wherein FIG. 1A shows an initial statewhere a user takes a handle and bends his body forwardly and FIG. 1Bshows an exercise state where the user pulls the handle toward his chestby applying a force in a state of taking the handle, while bending hisbody backwardly. As mentioned above, the rowing machine is widely usedfor training purposes for athletes, and since the user exercises in astate of sitting in the seat of the rowing machine, there is no harm tohis body. Thus, the rowing machine is also used for remedial purposes.The operating methods of the conventional rowing machine are carried outrepeatedly through the initial state as shown in FIG. 1A and theexercise state as shown in FIG. 1B.

However, even though the patient having spine injury, especially theparaplegic patient, makes use of the conventional rowing machine, hecannot move the seat backwardly by applying a force caused by his feetto the footboards and further cannot stretch his legs to pull thehandle. Therefore, the user places his feet on the floor and pulls thehandle by using only his both arms, as shown in FIG. 2. Thus, the rowingmachine as the whole body exercise machine serves as just an armexercise machine, such that the user cannot enjoy the rowing activities,unlike general persons having rowing activities through the rowingexercise. Since the simple arm exercises are repeatedly performed, thereare no exercise effects on the lower body, thereby losing his interestand fun and failing to keep exercising.

In order to solve these problems, as shown in FIG. 3, there is provideda rowing machine exercise-assisting device according to a firstembodiment of the present invention that includes a support part 10 anda seat 20 disposed on the support part 10 in such a manner as to beautomatically moved reciprocally. The support part 10 has a thinplate-like guide rail 11 disposed on the upper surface thereof so as tomove the seat 20 reciprocally in forward and backward directions. Theguide rail 11 has a width larger than the width in a directionperpendicular to the length direction of the support part 10 and has aslot formed at the center thereof along the length direction thereof.Further, the support part 10 has footboards 12 disposed at the left andright sides thereof so as to support a user's feet thereagainst in sucha manner as to be protruded outwardly toward the left and right sidesthereof. More particularly, the footboards 12 may be bent to a givenslant angle in a direction distant from the user so as to make theuser's feet conveniently placed thereon. The support part 10 has a shapeof a generally square column lying on the floor, but only if it isprovided with the linear type guide rail 11 and the footboards 12, itmay have any column shapes. The interior of the support part 11 isempty, and reciprocating exercise means 40, 50 or 60 as will bediscussed later is provided in the interior of the support part 11.

The footboards 12 on which the user's feet are placed have fixing belts(not shown) mounted on one surface thereof so as to firmly fix theuser's feet thereto, thereby preventing the user's feet from beingescaped therefrom during exercising.

The seat 20 is disposed on the guide rail 11 in such a manner as to beautomatically moved reciprocally. Preferably, the seat 20 includes amoving part 21 adapted to be mounted on the guide rail 11, aplate-shaped seating part 22 in which the user sits, and a back supportpart 23 adapted to support the user's back when sitting. The seatingpart 22 and the back support part 23 are coupled to each other by meansof elastic members 24 like springs so as to allow the back support part23 to be bent backwardly by a given angle when he leans his back againstthe back support part 23. Preferably, the moving part 21 is brought intodirect contact with the guide rail 11. Even though not shown in thedrawings, the moving part 21 has an engagement part 25 (See FIGS. 5 to7) disposed on the underside surface thereof. Preferably, the engagementpart 25 is engaged with the reciprocating exercise means 40, 50 or 60like a belt provided in the interior of the guide rail 11 and is movedforwardly and backwardly. As the engagement part 25 of the moving part21 is moved forwardly and backwardly, the seat 20 having the moving part21 mounted thereon is also moved forwardly and backwardly along theguide rail 11. The reciprocating exercise means is configured into avariety of shapes, which will be in detail discussed later.

Generally, since the user of the rowing machine exercise-assistingdevice according to the present invention is a paraplegic patient, hemay be fallen from the seat 20 by losing his body balance thereon duringthe reciprocating motions of the seat 20 in the forward and backwarddirections, which gives the risk of injuries to him. Thus, the seat 20further has a safety belt (not shown) mounted thereon to prevent theuser from being escaped from the rowing machine during the reciprocatingmotions of the seat 20.

According to the present invention, desirably, the rowing machineexercise-assisting device further includes a handle 30 to which acontroller is attached to control the automatic reciprocal motions. Thehandle 30 has a generally linear or curved rod-like shape like thehandle of the general rowing machine, and only if the handle 30 is takenby both hands of the user, it may have any shapes. First, the user takesthe handle 30 by his both hands and pulls the handle 30 toward hischest. At this time, as mentioned above, since the rowing machineexercise-assisting device according to the present invention is providedwith the automatically reciprocating seat 20, the seat 20 is movedforwardly and backwardly at a given speed along the guide rail 11. Ifthe seat 20 moves in the forward direction with respect to the user inthe state where the user's feet are placed on the footboards 12, hisknees are naturally bent, and contrarily, if the seat 20 moves in thebackward direction with respect to the user, his knees are naturallystretched out.

Therefore, the handle 30 is pulled by the user in accordance with theforward and backward movements of the seat 20, such that the user canhave rowing activities and dynamic rhythms like general persons freelyusing their lower body. In addition to the upper body exercise,especially the arm exercise performed in the conventional rowingmachine, the present invention can provide the lower body exercise tothe paraplegic patient through the automatically reciprocating seat,thereby giving the whole body exercise to him. Further, his knees areautomatically bent and stretched periodically, thereby preventing theheterotopic ossification by which the knee joints are hardened by theaccumulation of the calcium on the knees.

FIG. 4 is a sectional view showing the handle 30 of the rowing machineexercise-assisting device according to the first embodiment of thepresent invention. The handle has a control panel mounted thereon so asto allow the paraplegic user to easily control the reciprocating motionsof the seat 20, but if necessary, the control panel may be mounted on aseparate position and may be provided in a wired or wireless shape. Moreparticularly, the control panel mounted inside the handle 30 includes anon/off switch 31 adapted to control the start and stop of thereciprocating exercise of the seat 20, a speed adjustment switch 32adapted to adjust the speed of the reciprocating exercise of the seat 20and a distance adjustment switch 33 adapted to adjust the reciprocatingdistance of the reciprocating exercise of the seat 20. The positions ofthe respective switches as shown in FIG. 4 may be changed freely, and ifnecessary, additional function switches may be provided on the handle30. The distance adjustment switch 33 serves to adjust the reciprocatingdistance of the seat 20, and in this case, the reciprocating distance isthe maximum movement range of the seat 20 moving reciprocally along theguide rail 11. That is, if the reciprocating distance is set large, theseat 20 reciprocates in a relatively large range in forward and backwarddirections, and contrarily, if the reciprocating distance is set small,the seat 20 reciprocates in a relatively small range in forward andbackward directions. Therefore, the reciprocating distance of the seat20 is set in consideration of the lengths of the user's arms and legs.

Even the paraplegic user easily presses the switches 31 to 33 providedon the handle 30, so that the automatic reciprocating motions of theseat 20 of the rowing machine exercise-assisting device can be readilycontrolled.

Hereinafter, an explanation on the reciprocating exercise means 40, 50and 60 allowing the seat 20 of the rowing machine exercise-assistingdevice to be automatically reciprocated will be given with reference toFIGS. 5 to 7. The reciprocating exercise means 40, 50 and 60 aredisposed in the empty space in the support part 10, but they may bedisposed at an arbitrary position outside the support part 10.

FIG. 5 is a side sectional view showing the reciprocating exercise means40 provided at the inside of the support part 10 of the rowing machineexercise-assisting device according to the first embodiment of thepresent invention, and in this case, the reciprocating exercise means 40includes a timing belt 41. The timing belt 41 is a band-shaped belt onwhich concave and convex portions are formed regularly. In this case,the timing belt 41 is rotated in accordance with the rotation of a motor42, and as a result, the engagement part 25 of the moving part 21, whichis fixed to the timing belt 41, is moved forwardly and backwardly (inthe direction parallel to the surface on which the rowing machine isplaced). Desirably, the concave and convex portions formed on the timingbelt 41 are engaged with the concave and convex portion formed on theunderside surface of the engagement part 25 to allow the seat 20 to bemoved forwardly and backwardly by means of the timing belt 41 rotated bythe motor 42. The engagement part 25 does not have any limitation in theshape thereof, and only if it has the concave and convex portions formedon the underside surface thereof in such a manner as to be engaged withthe timing belt 41, it may have a variety of shapes. Further,preferably, the engagement part 25 is a protruded portion of the movingpart 21, which may be formed unitarily with the moving part 21, and moredesirably, the engagement part 25 may be connected directly with theunderside surface of the seating part 22 of the seat 20 in such a manneras to pass through the slot formed along the guide rail 11.

So as to permit the timing belt 41 to be circulated by means of themotor 42, moreover, the rowing machine exercise-assisting deviceaccording to the first embodiment of the present invention includes apulley disposed at the opposite side to the motor 42 so as to send thetiming belt 41 back to the motor 42. As a result, the timing belt 41 isrotated around the two shafts of the motor 42 and the pulley. The pulleydoes not have any limitation in the kind and shape, and only if it isrotated to be engaged with the timing belt 41, it may have any kind andshape.

Therefore, the moving directions of the moving part 21 and theengagement part 25 are determined in accordance with the direction ofthe rotation of the motor 42, and further, the moving direction of theseat 20 connected integrally with the moving part 21 is determined inaccordance with the moving direction of the moving part 21. Also, thereciprocating speed and distance are determined in accordance with therotating speed of the motor 42 and the moving distance of the timingbelt 41.

That is, if the direction of the rotation of the motor 42 is changedreversely, the seat 20 is moved to the opposite direction thereto. Sincethe motor 42 should repeat the forward and backward rotation for arelatively short period of time, it is generally composed of the servomotor having the controller through which the rotating speed and therotating direction are accurately controlled. Specifically, a BLDC motoris most desirably used as the motor 42 of the reciprocating exercisemeans 40 in the present invention in that the speed and torque can beeasily adjusted just by varying the time (phase difference) of thecurrent intermittence period of a basic driving circuit, no rectifierand brush giving bad influences in the life term by means of theabrasion caused by the mechanical friction is used, the life term issemi-permanently extended, and noise is generated a little therefrom.

As mentioned above, the motor 42 has the controller (not shown) mountedthereon, and preferably, the controller is connected to the switches 31to 33 formed on the control panel of the handle 30 in such a manner asto receive electrical signals transmitted when the user presses theswitches and to set the start/stop, the reciprocating speed, and thereciprocating distance in accordance with the received signals. As aresult, the motor 42 is operated in accordance with the set values,thereby allowing the seat 20 to be moved reciprocally.

FIG. 6 is a side sectional view showing reciprocating exercise means 50provided in the support part 10 of a rowing machine exercise-assistingdevice according to a second embodiment of the present invention. Inthis case, the reciprocating exercise means 50 includes a chain 51. Asmentioned above, the reciprocating exercise means 50 may be disposed atany positions outside the support part 10. A motor 52 has the samestructure, function and control method of the signals received from thehandle 30 as those of the motor 42 according to the first embodiment ofthe present invention, and therefore, an explanation on them will beavoided. According to the second embodiment of the present invention,instead of the timing belt 41, the chain 51 is circulated, andtherefore, instead of the pulley, a chain sprocket is adopted.

The chain 51 is rotated in accordance with the rotation of the motor 52,and as a result, the engagement part 25 of the moving part 21 of theseat 20, which are fixed to the chain 51, is moved forwardly orbackwardly. Desirably, the engagement part 25 of the moving part 21 hasprotrusion-like chain insertion portions formed regularly on theunderside surface thereof, as shown in FIG. 6. Therefore, desirably, thechain insertion portions are inserted into the empty space portionsarranged regularly on the chain 51, such that as the chain 51 isrotated, the engagement part 25 and the moving part 21 being engagedwith the chain 51 are moved and the seat 20 is thus moved. Preferably,the engagement part 25 is a protruded portion of the moving part 21,which is formed unitarily with the moving part 21, and alternatively,the engagement part 25 may be coupled with the moving part 21 by meansof a separate member and may be coupled directly with the undersidesurface of the seating part 22 of the seat 20 in such a manner as topass through the slot formed along the guide rail 11.

In the same manner as the first embodiment of the present invention,further, the moving direction, reciprocating speed and the reciprocatingdistance of the seat 20 are determined in accordance with the rotatingdirection (forward/backward rotation), the rotating speed, and thenumber of rotation of the motor 52.

FIG. 7 is a side sectional view showing reciprocating exercise means 60provided in the support part 10 of a rowing machine exercise-assistingdevice according to a third embodiment of the present invention. In thiscase, the reciprocating exercise means 60 has a configuration wherein alinear gear and a circular gear are engaged with each other. Asmentioned above, the reciprocating exercise means 60 may be disposed atany positions outside the support part 10. Preferably, the linear gearis a rack gear 61 and the circular gear is a pinion gear 63. The rackgear 61 is a linear band-like gear having protrusions (gear teeth)regularly formed along one side surface thereof, and the pinion gear 63is a disc-like gear having protrusions (gear teeth) regularly formedcircumferentially along the outer periphery thereof. The protrusions ofthe rack gear 61 and the protrusions of the pinion gear 63 are engagedwith each other. That is, the protrusions of the rack gear 61 areengaged with the slots between the protrusions of the pinion gear 63,and contrarily, the protrusions of the pinion gear 63 are engaged withthe slots between the protrusions of the rack gear 61. A motor 62, whichis connected to the pinion gear 63 to rotate the pinion gear 63, has thesame structure, function and control method of the signals received fromthe handle 30 as those of the motor 42 according to the first embodimentof the present invention, and therefore, an explanation on them will beavoided.

The rack gear 61 is desirably provided on the underside surface of themoving part 21 of the seat 20, and alternatively, it may be provideddirectly on the underside surface of the seating part 22 of the seat 20.The rack gear 61 is provided on the underside surface of the engagementpart 25 in FIG. 7, but it may be provided directly on the undersidesurface of the seating part 22 of the seat 20. The rack gear 61 and thepinion gear 63 are engaged with each other, and in more detail, the rackgear 61 performs a linear motion by receiving the rotating motion of thepinion gear 63. Therefore, in the same manner as the first and secondembodiments of the present invention, the rotation of the pinion gear 63is determined in accordance with the rotating direction(forward/backward rotation), the rotating speed, and the number ofrotation of the motor 62, and the moving direction, reciprocating speedand the reciprocating distance of the seat 20 connected to the rack gear61 are determined in accordance with the rotation of the pinion gear 63.

While the present invention has been described with reference to theparticular illustrative embodiments, it is not to be restricted by theembodiments but only by the appended claims. It is to be appreciatedthat those skilled in the art can change or modify the embodimentswithout departing from the scope and spirit of the present invention.

1. A rowing machine exercise-assisting device comprising: a guide rail;a support part adapted to support the guide rail; a seat mounted on theguide rail in such a manner as to move reciprocally in forward andbackward directions along the length direction of the guide rail, inwhich a user sits; a safety belt provided on the seat to prevent theuser from being escaped from the seat; footboards disposed on left andright sides of the support part to place the user's feet thereon at thetime when the user sits in the seat; a fixing belt provided on each ofthe footboards to prevent the user's foot from being escaped from thefootboard; a bar-shaped handle taken by the both hands of the user;reciprocating exercise means having a servo motor and a controllercontrolling the rotation of the servo motor; and a control panelprovided on the handle and connected to the controller to transmitcommands to the controller such that the controller controls therotating direction, the rotating speed and the number of rotation of theservo motor, the control panel having a switch adapted to control thestart and stop of the reciprocating exercise of the seat, a switchadapted to adjust the speed of the reciprocating exercise of the seatand a switch adapted to adjust the reciprocating distance of thereciprocating exercise of the seat, whereby as the servo motor rotatesforwardly and backwardly, the seat is automatically moved reciprocallyin the forward and backward directions along the length direction of theguide rail.
 2. The rowing machine exercise-assisting device according toclaim 1, wherein the reciprocating exercise means further comprises aband-shaped timing belt having concave and convex portions formedregularly thereon and a pulley adapted to be engaged with the timingbelt to circulate the timing belt therealong, the timing belt beingrotated in accordance with the rotation of the servo motor in the stateof being engaged with the servo motor and the pulley, and the seatcomprises an engagement part connected to the underside surface thereofand having concave and convex portions adapted to be engaged with theconcave and convex portions formed on the timing belt, such that as thetiming belt is rotated forwardly and backwardly, the seat isreciprocally moved in the forward and backward directions along thelength direction of the guide rail.
 3. The rowing machineexercise-assisting device according to claim 1, wherein thereciprocating exercise means further comprises a chain and a sprocketadapted to be engaged with the chain to circulate the chain therealong,the chain being rotated in accordance with the rotation of the servomotor in the state of being engaged with the servo motor and thesprocket, and the seat comprises an engagement part connected to theunderside surface thereof and having protrusions regularly formedthereon in such a manner as to be insertedly engaged with the emptyspace portions regularly arranged along the chain, such that as thechain is rotated forwardly and backwardly, the seat is reciprocallymoved in the forward and backward directions along the length directionof the guide rail.
 4. The rowing machine exercise-assisting deviceaccording to claim 1, wherein the reciprocating exercise means furthercomprises a disc-shaped circular gear rotatingly connected to the servomotor and having protrusions regularly formed circumferentially alongthe outer periphery thereof and a linear gear having a shape of a linearband and having protrusions adapted to be engaged with the circular gearso as to convert a rotating motion of the circular gear into a linearmotion, the linear gear being coupled to the underside surface of theseat in such a manner as to be disposed between the underside surface ofthe seat and the circular gear, such that as the circular gear isrotated forwardly and backwardly, the seat is reciprocally moved in theforward and backward directions along the length direction of the guiderail.
 5. The rowing machine exercise-assisting device according to claim2, wherein the reciprocating exercise means is disposed inside thesupport part.
 6. The rowing machine exercise-assisting device accordingto claim 1, wherein the seat further comprises a back support partadapted to support the user's back, and the back support part has anelastic restoring force in such a manner as to be bent backwardly when agiven force is applied thereto and to be returned to its originalposition when the given force is removed therefrom.